The primary objectives of this research are to prepare a wide variety of pentasubstituted and hexasubstituted phosphorus compounds. Methods for the production of P(V) compounds include a variety of cycloaddition reactions of P(III) and P(IV) compounds, biphilic insertion reactions into sigma bonds, and exchange reactions of P(V) compounds. The P(VI) compounds will be prepared by nucleophilic addition to a wide variety of P(V) compounds. It is anticipated that this research will yield a large number of materials with novel structure. These substances will be submitted for biological testing where this is appropriate. Other work will include studies of "pseudorotation" of these P(V) compounds, nmr investigations of their structure, and studies of their chemical properties and reactions.